office 365 calendar

Here's some background:

The problem is on a new Dell Laptop E7470, running Windows 10, and Office 365, on a college campus on a domain environment.

As a member of the IT Dept, all members are able to view and edit a shared out of office calendar, except myself. I get the popup message that I don't have permissions. However, I can go to our web app, and add info onto the shared calendar there.

Any ideas on what is set incorrectly on my system?

Thanks in advance!
Sandy